Use h2c from x/net to handle h2c requests

Co-authored-by: Mathieu Lonjaret <mathieu.lonjaret@gmail.com>

vendor/golang.org/x/net/publicsuffix/gen.go

@@ -100,6 +100,7 @@ var (
 	labelsList    = []string{}
 	labelsMap     = map[string]bool{}
 	rules         = []string{}
+	numICANNRules = 0
 
 	// validSuffixRE is used to check that the entries in the public suffix
 	// list are in canonical form (after Punycode encoding). Specifically,
@@ -167,11 +168,14 @@ func main1() error {
 		}
 		s = strings.TrimSpace(s)
 		if strings.Contains(s, "BEGIN ICANN DOMAINS") {
+			if len(rules) != 0 {
+				return fmt.Errorf(`expected no rules before "BEGIN ICANN DOMAINS"`)
+			}
 			icann = true
 			continue
 		}
 		if strings.Contains(s, "END ICANN DOMAINS") {
-			icann = false
+			icann, numICANNRules = false, len(rules)
 			continue
 		}
 		if s == "" || strings.HasPrefix(s, "//") {
@@ -287,7 +291,7 @@ func gitCommit() (sha, date string, retErr error) {
 
 func printTest(w io.Writer, n *node) error {
 	fmt.Fprintf(w, "// generated by go run gen.go; DO NOT EDIT\n\n")
-	fmt.Fprintf(w, "package publicsuffix\n\nvar rules = [...]string{\n")
+	fmt.Fprintf(w, "package publicsuffix\n\nconst numICANNRules = %d\n\nvar rules = [...]string{\n", numICANNRules)
 	for _, rule := range rules {
 		fmt.Fprintf(w, "%q,\n", rule)
 	}